And I'm Melissa Block. Republicans are reeling from the stunning news out of the Virginia GOP primary last night. Majority Leader Eric Cantor, the number two Republican in the U.S. Congress, was not just upset, he was beaten badly by a relatively unknown challenger. His name is David Brat. He's a college professor who used Tea Party backing to beat Cantor by 11 points. This is the first time in history a majority leader has lost a primary, and today Cantor addressed that loss. To talk about all this, NPR's Don Gonyea joins me here in the studio. And Don, let's start with the latest developments. Eric Cantor has said that he is going to step down as majority leader on July 31.

DON GONYEA, BYLINE: Exactly. He spoke on the hill, held a press conference late this afternoon after a meeting with his fellow Republicans in the Congress. And basically, he couldn't continue as leader. If he had, he really had of - would have had no power. He lost. He's a lame duck. So he steps down to clear the way for what he hopes might be an orderly succession. Again, he came out, spoke to reporters - he seemed to be coping with it just fine. He's had some time to let the news settle in, but he was asked about divisions within the GOP.

REPRESENTATIVE ERIC CANTOR: I do believe that what we have in common as Republicans is a tremendous amount of commitment to a better and smaller government, and greater opportunity and growth for everybody. And the differences that we may have are slight and pale in comparison to the differences that we have with the left and those expressing support for liberalism and a more expansive government.

GONYEA: Again - didn't say what he will be doing. He will step down at the end of July. The election to replace him will be held before that - wouldn't speculate as to why he lost - how he lost. He said he'll leave the political analyst to the rest of us.

BLOCK: To y'all, I think he said.

GONYEA: To y'all, yes.

BLOCK: Putting a good face on a really shocking defeat by the - from the - of the majority leader. What happens now though, Don? I mean he sort of sidestepped the question of who he favored to replace him in his job.

GONYEA: Right. He did say should the current majority whip Kevin McCarthy run, that he thinks he would be a great candidate. But again, he said he doesn't know who all is running. We do know that Congressman Pete Sessions of Texas has already announced his interest, but this is where it gets really interesting because there is now a vacuum. And this member - this leader who was the speaker in waiting, essentially, is now out of the picture. So it really leaves a wide open race. Maybe they'll go for an outsider. Maybe it'll be another establishment-type. But the Tea Party will certainly want to have a powerful say in this, given what has just happened in this race. Steve Stivers, a congressman from the Columbus Ohio area, was talking to some reporters and he said last night at one in the morning he got a text on his phone from someone saying, I hope you'll consider me. I'd like your support.

BLOCK: Oh, really?

GONYEA: So the jockeying began...

BLOCK: Right away.

GONYEA: Right. Before the papers hit the newsstand this morning.

BLOCK: Don, the U.S. House is no stranger to chaos and controversy, but today it does seems to be especially chaotic.

GONYEA: It sure does. And, you know, everybody's trying to figure out what this means going forward, not just for the leadership, but for other members and for the whole legislative agenda. There a whole lot of primaries, yet, still to come. One Congressman, Lee Terry of Nebraska, talking to CNN this morning said, it has just sent shivers through the entire Republican Congress. Everybody's trying to analyze it. One reason that Congressman Terry was so candid, is that he's already had his primary. He barely beat a tea party candidate back home a month ago. He has to be looking at the Cantor result and wondering if he, perhaps, could have suffered the same fate. He barely won.

BLOCK: Yeah, and briefly, Don, I mean there had been a lot of talk that the Tea Party was moribund. Do we have to rewrite that story now?

GONYEA: Well, they're alive and kicking, I think we have to say. They can certainly point to Cantor, and they're looking ahead to a Mississippi run off in just a couple of weeks, where they could very well help knock off a six-term incumbent, US Senator Thad Cochran. As far as Cantor goes, you know, it's important to note here that there were a lot of factors. The Tea Party was energized, but he was also seen as being kind of distant. So it's hard to pin down exactly what beat him.